Conduit bending apparatus



Dec. 24, 1968 Filed May 23, 1966 G. C. ENSLEY CONDUIT BENDING APPARATUS 2 Sheets-Shet 1 o mm INVENTOR.

A TTOR NEK) GLOVER c; ENSZEY Dec. 24, 1968 G. c. ENSLEY 3,417,590

CONDUIT BENDING APPARATUS Filed May 23, 1966 2 Sheets-Sheet 2 O In INVENTOR. GLOVE R C. ENSLE Y I A TTORNEYS United States Patent 3,417,590 CONDUIT BENDING APPARATUS Glover C. Ensley, 525 N. Woodland Drive, Kansas City, Mo. 64118 Filed May 23, 1966, Ser. No. 551,991 9 Claims. (Cl. 72157) This invention relates to improved apparatus for bending electric power cable conduit and the like.

The principal objects of the present invention are: to provide conduit bending apparatus which is easily moved from place to place; to provide such apparatus which is adapted to selectively bend tube or conduit either on a horizontal or vertical axis; to provide such apparatus wherein bending reels are easily interchangeable for producing different bend radii or handling different conduit; to provide such apparatus which includes structure preventing bending reels from being accidentally mounted on the driving structure incorrectly; to provide such a bending device which permits the angle of bend to be preset whereby the device automatically stops up on pro ducing the desired angle of bend; to provide such apparatus which includes a gauge to set the position of the ensuing bend from the tip of the conduit; to provide a bend measuring device which comprises a simple switch mounted on a clamp adapted to be secured on the periphery of the bending frame in alignment with a resiliently mounted trigger secured to the rotating bending reel; to provide such a device which includes storage means for an additional bending reel and a conduit supporting member to match same; to provide such apparatus wherein the conduit supporting member is easily pivoted out of supporting osition to facilitate removal of the bent pipe from the bending reel; and to provide such apparatus which is simple and rugged in construction and well suited for its intended purpose.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.

FIG. 1 is a front elevational view of bending apparatus embodying this invention showing alternate positions of the operating conduit support and a typical bend.

FIG. 2 is a side elevational view of the apparatus showing alternate positions of the bend-to-tip distance gauge.

FIG. 3 is a front elevational View of the apparatus with the bending reel and front cover removed and portions broken away particularly ShOWing the power train and reel mounting structure.

FIG. 4 is a front elevational view on a slightly enlarged scale showing the rear face of a typical bending reel.

FIG. 5 is a fragmentary side elevational view on an enlarged scale particularly showing the bend limiting switch positioned on the curved periphery of the apparatus frame.

Referring to the drawings in more detail:

The reference numeral 1 generally indicates bending apparatus embodying this invention. The apparatus 1 comprises a rigid frame member 2 to which is rotatably mounted suitable spaced apart wheels 3. Parallel bars 4 extend upwardly and rearwardly of the frame member 2 and support a cross bar 5 in a convenient position for grasping to move the apparatus. Further, the cross bar portion 5 is located in the same rear plane with respect to the apparatus as the rear outer edge of the wheels 3 whereby the apparatus may selectively lie fiat on the ground supported on the wheels 3 and the cross bar 5. Normally, the apparatus is supported vertically on the wheels 3 and a forwardly and downwardly directed pair of extensions 6 as best illustrated in FIG. 2.

A reversible motor 7 is fixed to the frame 2 and drives a worm 8 engaged with a worm gear 9. The worm gear 9 is pivotally mounted on the rear face of the frame 2 and is fixed with respect to a sprocket 10 which is of smaller diameter than the gear 9 and is also positioned on the rear face of the frame 2. A chain 11 is engaged with the sprocket 10, a chain tightener' 11 and a sprocket 12 rotatably mounted on a shaft 13 extending through the frame 2. The shaft 13 carries a sprocket 14 positioned on the front face of the frame. The sprocket 14 is engaged with a chain 15 which is engaged with a large wheel member or sprocket wheel 16. The sprocket wheel 16 rotates about a stub shaft 17 rigidly mounted to the frame 2 by means of heavy cross braces 18. As the motor 7 rotates, the various power transmitting elements produce approximately a 5,000 to 1 ratio between the motor and sprocket wheel 16 whereby the sprocket wheel makes approximately one revolution in seconds under an average bending load. A chain tightener in the form of an idler wheel 19 is mounted on the frame 2 in contact with the chain 15. The idler wheel 19' also maintains maximum contact between the teeth of the sprocket 14 and links of the chain 15 for the space provided.

The stub shaft 17 extends through the sprocket wheel 16 and has a circular groove 20 radially extending thereinto for a reason noted below. The sprocket wheel 16 has large circular cut-out portions 21 which function to lighten the apparatus without significantly detracting from the strength of the sprocket wheel. Between the cut-out portions 21 and offset from the axis of the stub shaft 17, bores 22 extend through the sprocket wheel and, in this example, are degrees from each other about the stub shaft 17.

A bending reel 23 has three bending grooves respectively designated 24, 25 and 26 which are adapted to respectively receive one-half, three-fourths and one-inch diameter conduit for bending. The bending reel 23 has a central opening or bore 25 adapted to slidably telescope over the forwardly projecting portion of the stub shaft 17 for rotatably mounting the bending reel on the stub shaft 17. The bending reel 23 includes four rigid draft studs 26' extending axially rearwardly from the rear face of the reel on a bolt circle which corresponds to the bores 22 in the sprocket wheel 16. When the bending reel 23 is telescoped onto the stub shaft 17, the respective studs 26 are received into the bores 22 which provide the rotational driving relationship for bending conduit in the apparatus.

A blocking bar 27 is rigidly mounted in one of the cutout portions 21 to prevent the apparatus operator from accidentally causing the studs 26' to enter the cut-out portions 21 instead of the bores 22 when mounting the bending reel on the stub shaft 17. Since the reel is rotatably driven through the studs 26, it only remains to insure that the bending reel cannot accidentally move axially with respect to the sprocket wheel 16 so as to produce disengagement during operation. Thus, a lift pin 28 is provided on the boss 29 of the bending reel. The lift pin 28 cooperates with a helical spring 30 which normally urges the pin radially inwardly whereby the end 31 thereof extends into the bore 25. When the bending reel is telescoped over the stub shaft 17, the pin 28 is lifted so that the stub shaft 17 may be received in the bore 25 without obstruction. When the bending reel 23 has reached its terminal position with the studs 26' received in the bores 22, the pin 28 is aligned with the groove 20 and released whereby the end 31 enters the groove 20 to maintain the bending reel axially fixed with respect to the stub shaft 17 and adjacent the sprocket wheel 16. In order to remove the bending reel 23, it is only necessary to lift the pin 28 and axially withdraw the reel from the stub shaft. A second bending reel 32, for example, adapted to bend 1 /2- inch and 2-inch conduit is stored on a rearward extension 33 of the stub shaft 17.

The reels each include suitable hook or retainer portions 34 secured thereto for receiving the conduit 35 in alignment with a selected bending groove. The respective retainer portion grasps the conduit as the reel rotates in the direction indicated by the arrow 36 (FIG. 1) whereupon the conduit follows along a selected bending groove. The conduit is prevented from moving out of the bending groove during reel rotation by a conduit support 37 which, in operative position, extends upwardly from the frame extension 6 on the upstream side of the bending reel below the axis thereof. The conduit support, in this example, includes an elongated body having suitable rollers 38 at one end thereof which cradle the conduit tangentially of the respective bending grooves and permit easy motion of the conduit therepast. The conduit support 37 is hinged at the other end 39 thereof which permits the support to pivot laterally outwardly and downwardly to the position indicated by the broken lines 40, but prevents the support from pivoting inwardly or toward the reel beyond the upright position so as to maintain rolling or sliding support of the conduit during bending. A hinge pin 41 has a grasping head thereon and is adapted to be axially withdrawn as indicated at 42 for completely removing the conduit support 37 when a different reel is to be used for bending. In this event, a second conduit support 43 replaces the support 37. The support 43 is stored adjacent the opposite extension 6 by means of a hinged connection using a removable hinge pin 43'.

Sleeves 44 and 44' are rigidly secured to the frame 2 at horizontally spaced apart positions on the rear thereof and telescopically receive a rod 45 adapted to selectively slide laterally outwardly of the apparatus. A gauge 46 is secured to the end of the rod 45 and is adapted to move therewith outwardly of the apparatus to a desired position. The gauge 46 includes a blade 46' which is adapted to swing, upon rotation of the rod 45, in a plane extending normally of the unbent conduit 35 when received in a bending groove and supported by the conduit support 37. Thus, the blade 46' acts as a stop for positioning the end 47 of the unbent conduit. A sleeve 48 is slidable on the rod 45 between the sleeves 44 and 44' and has a thumb screw 48' for selectively locking the sleeve 48 in a desired position along the rod 45. A helical compression spring 49 surrounds the rod 45 and bears against the sleeve 48 and the sleeve 44 permitting the blade 46' to move slightly outwardly to provide clearance for the upward movement of the end -47. The spring 49 also maintains the blade 46' substantially in the desired rotary position after lateral and rotary adjustment by urging the sleeve 48 tightly but resiliently against the fixed sleeve 44.

The frame of the apparatus has a semicircular periphery 50 at the upper portion thereof and which houses a major part of the sprocket wheel 16 and chain 15. A front cover 51 normally covers the power train members at the front of the apparatus which are not covered by the bending reel 23. A suitable curved scale 52 is marked in degrees of bend and is positioned adjacent the upper periphery of the bending reel. A marker 53 is engaged with the reel and extends outwardly therefrom to indicate the position of the reel with respect to the scale. The marker 53 has a base portion in the form of a spiral spring and an indicator portion 54 which extends radially outwardly past the periphery of the reel. The base portion maintains the indicator portion in its radially extending position but permits the indicator portion to be resiliently moved about the mounting anchor 54' when contacted. The marker 53 is positioned on the reel so that it indicates zero on the scale 52 when the unbent conduit is engaged with the retainer portion 34 and the conduit support 37.

A push button actuated switch 55 is secured to a movable support or clamp bracket 56 which has parallel feet 57 and 58 extending outwardly therefrom and spaced apart a distance somewhat greater than the thickness of the frame 2 at the semicircular periphery 50. The leg 58 has a finger operated clamp screw 59 threadedly engaged therewith and extending therethrough. The screw 59 is adapted to contact the back side 60 of the frame 2 so as to urge the leg 57 against the face or front side 61, thus clamping the bracket 56 on the periphery 50. The switch 55 has an actuating button 62 which is positioned forwardly of the face 61 when the clamp bracket 56 is properly secured to the peripheral portion 50. The button 62 is maintained in alignment with the curved path taken by the marker portion 54 as the reel 23 rotates during conduit bending. By placing the clamp bracket 56 at a desired location on the periphery 50 with reference to the scale 52, the marker 54 will contact the button 62 when the reel has progressed through a predetermined bending angle. The switch 55 is electrically connected to conventional control relay devices (not shown) which are contained in a switch box 63 mounted on the back side of the frame 2 and are responsive to the pressing of the button 62 for deactuating the motor 7. Also contained in the switch box 63 are rectifiers for converting AC. to DC. for driving the motor 7 and conventional electrical devices (not shown) which produce electric braking of the motor 7 when the button 62 is pressed. A cord 64 connects into the switch box 63 and terminates in a push button control 65 which may be held in the operators hand and actuates the motor 7 when pressed, the operation of the motor 7 being overridden by the switch 55. A master switch '66 controls the power input to the motor 7 and electrical controls and the direction of the motor. A conventional electrical lead-in (not shown) supplies power to the apparatus.

In operation, the gauge 46 is positioned laterally of the apparatus so as to present a stop for axially positioning the end of the conduit 35 with respect to the bend to be produced therein. The conduit is normally placed in the apparatus by moving same axially along the conduit support 37, through the retainer portion 34 and against the stop blade 47. The switch 55 is placed in a desired position on the periphery 50 corresponding to the bend to be placed in the conduit. The master switch 66 is turned on and set for forward motion and the control 65 actuated. The motor 7 then drives the bending reel 23 in the direction indicated by the arrow 36 whereupon the retainer portion 34 maintains the conduit tightly in the selected bending groove as the reel rotates. The helical spring 49 permits the end of the conduit to move smoothly upwardly without interference from the balde 46'. When the marker portion 54 strikes the button 62, the motor 7 is deactuated, stopping the rotation of the reel 23 with the bent conduit in the bending groove. The conduit support 37 is then pivoted downwardly to the position indicated at 40, thus releasing the bent conduit to permit radial and axial movement of the conduit for removing same from the bending reel. After conduit removal, the bending reel may be conveniently returned to the beginning position by resetting the master switch to reverse, overriding the switch 55 by a push button control 67 and actuating the switch 65. The above steps may be performed with the reel axis either horizontal or vertical as desired by supporting the apparatus either on the bar 5 or extensions 6.

It is to be understood that, if desired, a bending reel may be provided with multiple grooves all of the same cradle curvature and radius from the center of the reel whereby multiple lengths of conduit of the same diameter may be simultaneously bent through the same angle. Also, the bending reel 23- may be easily removed and replaced with another reel, for example, the second reel 32 and the corresponding conduit support, such as support 43, placed in operable position quickly and easily. It is to be further understood that although one form of this invention has been illustrated and described, it is not to be limited thereto except insofar as such limitations are included in the following claims.

What I claim and desire to secure by Letters Patent is:

1. Portable bending apparatus comprising:

(a) a frame having a bending reel supporting shaft thereon, a pair of spaced apart wheels rotatably mounted on said frame on a common axis extending transversely of said shaft and spaced therefrom,

(b) a bar member rigidly mounted on said frame and spaced from said shaft, said bar member being positioned with respect to said wheels for supporting said shaft vertically when said bar member and wheels are resting on the ground, and

(c) means on said frame and spaced from said wheels, said means being positioned for supporting said shaft horizontally when said means and wheels are resting on the ground.

2. The apparatus as set forth in claim 1 wherein:

(a) said bar member is a handle bar extending parallel to said wheel axis.

3. Bending apparatus comprising:

(a) a frame, a prime mover mounted on said frame, a power train operably associated with said prime mover, said power train including a wheel member rotatably mounted on said frame and rotating on an axis in response to the operation of said prime mover.

(b) said wheel member having a first draft member associated therewith and offset from said axis, a bending reel removably rotatably mounted with respect to said frame and coaxially with said wheel member, said bending reel having a second draft member associated therewith and corresponding in offset position to said first draft member, and

() means for selectively retaining said bending reel adjacent said wheel member whereby said first and second draft members are opera-bly engaged causing said bending reel to rotate with said wheel member.

4. The apparatus as set forth in claim 3 wherein:

(a) said draft members comprise a stud and a matching bore for receiving said stud therein.

5. The apparatus as set forth in claim 3 wherein:

(a) a stub shaft is fixed to said frame and rotatably mounts said wheel member, said stub shaft extending axially through said wheel member,

(b) said bending reel is axially received on said shaft for rotation thereabout,

(c) said shaft has a radial groove extending thereinto,

and

(d) a pin is radially mounted in said bending reel and adapted to selectively radially extend into said groove for axially retaining said bending reel on said shaft adjacent said wheel member.

6. The apparatus as set forth in claim 3 wherein:

(a) said wheel member has lightening openings circumferentially spaced thereabout, said first draft member comprising a plurality of oircumferentially spaced bores, said second draft member comprising a plurality of circumferentially spaced studs simultaneously receivable in said respective bores, and

(b) a blocking member is secured across one of said bending reel rotatably mounted on said frame and a tube support aligned with said bending reel:

(a) a tube tip measuring gauge, said gauge comprising a rod telescopically mounted on said frame for movement transversely of said bending reel, and

(b) a blade mounted on said rod for selective swinging movement in a plane normal to a line extending between said tube support and said reel, said blade being positionable to selectively contact the tip of an unbent tube which simultaneously engages said tube support and said reel.

8. Bending apparatus comprising:

(a) a frame, bending reel rotatably mounted on said frame, said frame having a semicircular periphery portion adjacent said bending reel, a scale on said apparatus adjacent said peripher portion for indicating the relative rotational position of said reel with respect to said frame, drive means associated with said frame and rotatably driving said bending reel,

(b) a movable support adapted for mounting on said periphery in selective positions corresponding to said scale, drive control means on said support, and

(c) actuating means on said reel and adapted to actuate said control means when said reel has traversed an angle determined by the position of said support, said drive control means being operatively connected to said drive means for deact-uating same.

9. In a tube bending apparatus having a frame and a driven bending reel rotatably mounted on said frame:

(a) a tube support, said tube support comprising an elongated body having tube cradle means at one end thereof and normally ina position aligned with said bending reel, and

(b) hinge means at the other end of said body and hingedly connecting said body to said frame, said hinge means being adapted to prevent movement of said cradle means from said normal position toward said bending reel, but permitting selective pivoting movement of said cradle means in a direction laterally away from said reel and said normal position.

References Cited UNITED STATES PATENTS 1,899,281 2/1933 Lidseen 72159 2,784,762 3/1957 Carlson 72-413 2,921,619 1/1960 Bank 72218 3,238,762 3/1966 Maring 72-408 CHARLES w. LANHAM, Primary Examiner. 

1. PORTABLE BENDING APPARATUS COMPRISING: (A) A FRAME HAVING A BENDING REEL SUPPORTING SHAFT THEREON, A PAIR OF SPACED APART WHEELS ROTATABLY MOUNTED ON SAID FRAME ON A COMMON AXIS EXTENDING TRANSVERSELY OF SAID SHAFT AND SPACED THEREFROM, (B) A BAR MEMBER RIGIDLY MOUNTED ON SAID FRAME AND SPACED FROM SAID SHAFT, SAID BAR MEMBER BEING POSITIONED WITH RESPECT TO SAID WHEELS FOR SUPPORTING SAID SHAFT VERTICALLY WHEN SAID BAR MEMBER AND WHEELS ARE RESTING ON THE GROUND, AND (C) MEANS ON SAID FRAME AND SPACED FROM SAID WHEELS, SAID MEANS BEING POSITIONED FOR SUPPORTING SAID SHAFT HORIZONTALLY WHEN SAID MEANS AND WHEELS ARE RESTING ON THE GROUND. 